The present invention is related to a drawn cup roller bearing used in a vehicular transmission and various types of industrial machineries.
In a related drawn cup roller bearing in which a cage for holding rollers is assembled into an outer ring having ribs at opposite ends, one of the ribs at one end is formed by being bent in almost perpendicular to a raceway surface of the outer ring and a space defined between the rib, the outer ring and the rollers is formed as a lubricant retaining space. The rib at the other end is formed by being bent inwardly so as to be almost parallel to the raceway surface so that the cage is assembled into the outer ring from the side of this rib.
When the cage and the rollers in a state which these are set together are assembled into the outer ring, a part of the one of the ribs is abutted against the cage, and a part of the other rib is abutted against the rollers. Therefore, in the case that a load is applied to the rollers in an axial direction, since movement of the rollers in the axial direction is restricted, both the rollers and the cage are prevented from falling off from the outer ring (see JP2005-172037A).
However, in the related drawn cup roller bearing, the rollers may come over the rear side bent rib which is bent inwardly so as to be almost parallel to the raceway surface when the rollers expand an inscribed circle shape of the outer ring during an insertion of a shaft, thereby the function of preventing the rollers from falling off is insufficient. Further, if the rollers may come over the rear side bent rib due to the skew of the rollers at the time of use, and clearances are formed between the part of the rear side bent rib and the rollers and between an outer circumferential surface of the cage and an inner circumferential surface of the rear side bent rib by an axial load of the rollers, grease inside the bearing may flow out to the exterior from the clearances.